Caugant D.A.,Norwegian Institute of Public Health | Caugant D.A.,University of Oslo | Kristiansen P.A.,Norwegian Institute of Public Health | Wang X.,Centers for Disease Control and Prevention | And 7 more authors.PLoS ONE | Year: 2012

Background: The serogroup A conjugate meningococcal vaccine, MenAfriVac, was introduced in mass vaccination campaigns in December 2010 in Burkina Faso, Mali and Niger. In the coming years, vaccination will be extended to other African countries at risk of epidemics. To document the molecular characteristics of disease-causing meningococcal strains circulating in the meningitis belt of Africa before vaccine introduction, the World Health Organization Collaborating Centers on Meningococci in Europe and United States established a common strain collection of 773 isolates from cases of invasive meningococcal disease collected between 2004 and 2010 from 13 sub-Saharan countries. Methodology: All isolates were characterized by multilocus sequence typing, and 487 (62%) were also analyzed for genetic variation in the surface antigens PorA and FetA. Antibiotic susceptibility was tested for part of the collection. Principal Findings: Only 19 sequence types (STs) belonging to 6 clonal complexes were revealed. ST-5 clonal complex dominated with 578 (74.8%) isolates. All ST-5 complex isolates were remarkably homogeneous in their PorA (P1.20,9) and FetA (F3-1) and characterized the serogroup A strains which have been responsible for most epidemics during this time period. Sixty-eight (8.8%) of the 773 isolates belonged to the ST-11 clonal complex which was mainly represented by serogroup W135, while an additional 38 (4.9%) W135 isolates belonged to the ST-175 complex. Forty-eight (6.2%) serogroup X isolates from West Africa belonged to the ST-181 complex, while serogroup X cases in Kenya and Uganda were caused by an unrelated clone, ST-5403. Serogroup X, ST-181, emerged in Burkina Faso before vaccine introduction. Conclusions: In the seven years preceding introduction of a new serogroup A conjugate vaccine, serogroup A of the ST-5 clonal complex was identified as the predominant disease-causing strain.

Neglected Infectious Diseases (NID) such as trypanosomiasis, leishmaniasis, schistosomiasis and soil-transmitted helminthiasis receive less than 5% of the global investment for tropical diseases research. Clinical praxis in disease-endemic countries (DEC) is rarely evidence based and does not make use of the latest innovations in diagnostic technology. NIDrelated research on diagnostics is particularly underfunded, and diagnostic tools are lacking for a number of NID.
The aim of this proposal is to bridge the gap between existing technological innovation in diagnostics and clinical care practice for NID in resource-poor settings. The specific objectives are to develop simple, cost-effective diagnosis-treatment algorithms for three NID-related clinical syndromes: the persistent fever, the neurological and the digestive syndromes. Evidence-based algorithms for the primary care level will be designed with a patient-centred approach, following guidance from DEC stakeholders and making the best possible use of existing assays and treatments. Relevant diagnostic technology and diagnostic platforms will be introduced according to the specific epidemiological contexts in Africa and South-Asia.
The research consortium brings together a network of clinical epidemiologists, a diagnostics development group, several partners from academia and SMEs. The consortium further includes workpackages on reference laboratory, economic evaluation, quality assurance and translation to policy.
By developing accurate and affordable diagnostic platforms and by optimizing diagnostic-treatment algorithms, this project will rationalise treatment use, circumvent progression to severe presentations and thereby reduce NID morbidity/mortality and hinder the emergence of resistances. The project will result in two main deliverables: policy recommendation for health authorities in DEC, and a series of innovative diagnostic platforms.

Although Drug resistance tuberculosis is not a new phenomenon, Mali remains one of the blank countries without systematic data.Between 2006 and 2014, we enrolled pulmonary TB patients from local TB diagnostics centers and a university referral hospital in several observational cohort studies. These consecutive patients had first line drug susceptibility testing (DST) performed on their isolates. A subset of MDR was subsequently tested for second line drug resistance.A total of 1186 mycobacterial cultures were performed on samples from 522 patients, including 1105 sputa and 81 blood samples, yielding one or more Mycobacterium tuberculosis complex (Mtbc) positive cultures for 343 patients. Phenotypic DST was performed on 337 (98.3%) unique Mtbc isolates, of which 127 (37.7%) were resistant to at least one drug, including 75 (22.3%) with multidrug resistance (MDR). The overall prevalence of MDR-TB was 3.4% among new patients and 66.3% among retreatment patients. Second line DST was available for 38 (50.7%) of MDR patients and seven (18.4%) had resistance to either fluoroquinolones or second-line injectable drugs.The drug resistance levels, including MDR, found in this study are relatively high, likely related to the selected referral population. While worrisome, the numbers remained stable over the study period. These findings prompt a nationwide drug resistance survey, as well as continuous surveillance of all retreatment patients, which will provide more accurate results on countrywide drug resistance rates and ensure that MDR patients access appropriate second line treatment.

Performance of the malaria Rapid Diagnostic Test (RDT) OptiMal-IT was evaluated in Mauritania where malaria is low and dependent on a short transmission season. Slide microscopy was considered as the reference method of diagnosis. Febrile patients with suspected malaria were recruited from six health facilities, 3 urban and 3 rural, during two periods (December 2011 to February 2012, and August 2012 to March 2013). Overall, 780 patients were sampled, with RDT and thick blood film microscopy results being obtained for 759 of them. Out of 774 slides examined, of which 200 were positive, P. falciparum and P. vivax mono-infections were detected in 63.5% (127) and 29.5% (59), while P. falciparum/P. vivax coinfections were detected in 7% (14). Both species were observed in all study sites, although in significantly different proportions. The proportions of thick blood film and OptiMal-IT RDT positive individuals was 26.3% and 30.3% respectively. Sensitivity and specificity of OptiMal-IT RDT were 89% [95% CI, 84.7-93.3] and 91.1% [88.6-93.4]. Positives and negative predictive values were 78.1% [72.2-83.7] and 95.9% [94.1-97.5]. These diagnostic values are similar to those generally reported elsewhere, and support the use of RDTs as the main diagnostic tool for malaria in Mauritanian health facilities. In the future, choice of RDTs to be used must take account of thermostability in a hot, dry environment and their ability to detect P. falciparum and P. vivax.

In many parts of sub-Saharan Africa, urogenital and intestinal schistosomiasis co-occur, and mixed species infections containing both Schistosoma haematobium and S. mansoni can be common. During co-infection, interactions between these two species are possible, yet the extent to which such interactions influence disease dynamics or the outcome of control efforts remains poorly understood.Here we analyse epidemiological data from three West African countries co-endemic for urogenital and intestinal schistosomiasis (Senegal, Niger and Mali) to test whether the impact of praziquantel (PZQ) treatment, subsequent levels of re-infection or long-term infection dynamics are altered by co-infection. In all countries, positive associations between the two species prevailed at baseline: infection by one species tended to predict infection intensity for the other, with the strength of association varying across sites. Encouragingly, we found little evidence that co-infection influenced PZQ efficacy: species-specific egg reduction rates (ERR) and cure rates (CR) did not differ significantly with co-infection, and variation in treatment success was largely geographical. In Senegal, despite positive associations at baseline, children with S. mansoni co-infection at the time of treatment were less intensely re-infected by S. haematobium than those with single infections, suggesting competition between the species may occur post-treatment. Furthermore, the proportion of schistosome infections attributable to S. mansoni increased over time in all three countries examined.These findings suggest that while co-infection between urinary and intestinal schistosomes may not directly affect PZQ treatment efficacy, competitive interspecific interactions may influence epidemiological patterns of re-infection post-treatment. While re-infection patterns differed most strongly according to geographic location, interspecific interactions also seem to play a role, and could cause the community composition in mixed species settings to shift as disease control efforts intensify, a situation with implications for future disease management in this multi-species system.

PubMed | University of Amsterdam, University Of Science Des Techniques Et Des Technologies Of Bamako Usttb, University of Oxford and Institute National Of Recherche En Sante Publique InrspType: | Journal: Journal of ethnopharmacology | Year: 2015

Plants have contributed to food security and disease treatments to rural populations in sub Saharan Africa for many centuries. These plants occupy a significant place in the treatment of diseases, such as malaria. In Mali, malaria is the leading cause of medical consultation and death. This infection is particularly dangerous for pregnant women and children under 5 years. The general aim of this research was to collect data on the knowledge of traditional health practitioners on malaria in the Slingu area; particularly to document how traditional healers conceptualize and diagnose malarial disease and to collect and identify medicinal plants or other substances used for their health and well-being.An ethnobotanical survey was conducted on simple and complicated malaria in six villages in Slingu subdistrict in a period of 2 months. The ethnobotanical data was collected by means of semi-structured interviews and questionnaires. In total 50 traditional healers were interviewed.Two concepts of malaria (simple and complicated malaria) were cited and 97 plants used to treat malaria were identified. Decoctions and bathing (whole body) proved to be the most commonly used mode of application. Food attitudes and mosquitoes are perceived to be the most important causes of the disease. Trichilia emetica, Mitragyna inermis, Sarcocephalus latifolius, Cassia sieberiana, Cochlospermum tinctorium, Anogeissus leiocarpa, Guiera senegalensis and Entada africana were quoted as the most used in the treatment of malaria.Knowledge about malaria and traditional treatment practices exist in Slingu subdistrict. Herbal remedies are commonly used by people for the treatment of malaria because they are believed to be cost-effective and more accessible. Many of the plant species used for the treatment of malaria have not been well documented as well as their phytochemical and antimalarial activity.

The objective of this work was to describe the epidemiology of schistosomiasis 10 years after mass administration of praziquantel began in Sotuba, Mali.This observational cross-sectional survey in Sotuba, a periurban village in the Bamako district, took place from July to September 2010 and collected stool and urine samples from residents at least one year old. Kato-Katz (for stool) and urine filtration techniques were used to detect Schistosoma mansoni and S. hmatobium eggs, respectively. Overall, 335 urine samples and 300 stool samples were examined. The prevalence rate was 5.4% (18/335) for S. hmatobium and 8.7% (26/300) for S. mansoni. Excretion of these eggs was most frequent in the 6-15 year-old group: 4.8% (16/335) for S. hmatobium and 7.7% (23/300) for S. mansoni. Snails of the Biomphalaria pfeifferi and Bulinus truncatus species were the intermediate hosts, captured in the fields at water contact points. The principal clinical symptoms reported by participants were abdominal pain 27.2% (61/169) and headaches 23.2% (52/169).Despite the implementation of mass drug administration in Mali a decade ago, our results show that schistosomiasis transmission continues in Sotuba. Assessment of the risk factors for this persistent transmission is strongly needed.